ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/soc/xilinx/Kconfig b/drivers/soc/xilinx/Kconfig
new file mode 100644
index 000000000..49d69d6e1
--- /dev/null
+++ b/drivers/soc/xilinx/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "Xilinx SoC drivers"
+
+config ZYNQMP_POWER
+	bool "Enable Xilinx Zynq MPSoC Power Management driver"
+	depends on PM && ZYNQMP_FIRMWARE
+	default y
+	select MAILBOX
+	select ZYNQMP_IPI_MBOX
+	help
+	  Say yes to enable power management support for ZyqnMP SoC.
+	  This driver uses firmware driver as an interface for power
+	  management request to firmware. It registers isr to handle
+	  power management callbacks from firmware. It registers mailbox client
+	  to handle power management callbacks from firmware.
+
+	  If in doubt, say N.
+
+config XLNX_EVENT_MANAGER
+	bool "Enable Xilinx Event Management Driver"
+	depends on ZYNQMP_FIRMWARE
+	default ZYNQMP_FIRMWARE
+	help
+	  Say yes to enable event management support for Xilinx.
+	  This driver uses firmware driver as an interface for event/power
+	  management request to firmware.
+
+	  If in doubt, say N.
+endmenu